(iOS?) Can't read/observe/write

[jcbrtl]

The code runs on Android and works perfectly. On iOS, trying to read/observe/write chars, it throws (not so friendly):

BleException: The operation couldn’t be completed. (rx_ble.Errors error 1.)
0   plugin_scaffold                     0x0000000102a2bb78 $s15plugin_scaffold14serializeErrorySo07FlutterD0CypF + 316
1   plugin_scaffold                     0x0000000102a2cde0 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctFyycfU_ + 328
2   plugin_scaffold                     0x0000000102a2ceec $sIeg_IeyB_TR + 52
3   plugin_scaffold                     0x0000000102a2b2f8 +[PluginScaffoldHelper tryCatch:onCatch:onElse:] + 108
4   plugin_scaffold                     0x0000000102a2cc70 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctF + 624
5   plugin_scaffold                     0x0000000102a2f65c $s15plugin_scaffold20createPluginScaffold9messenger11channelName9methodMapSo20FlutterMethodChannelCSo0K15BinaryMessenger_p_SSSDySSypGtFySo0kL4CallC_yypSgctcfU_yycfU_ + 4476
6   plugin_scaffold                     0x0000000102a2cd08 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctFyycfU_ + 112
7   plugin_scaffold                     0x0000000102a2ceec $sIeg_IeyB_TR + 52
8   plugin_scaffold                     0x0000000102a2b2f8 +[PluginScaffoldHelper tryCatch:onCatch:onElse:] + 108
9   plugin_scaffold                     0x0000000102a2cc70 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctF + 624
10  plugin_scaffold                     0x0000000102a2e448 $s15plugin_scaffold20createPluginScaffold9messenger11channelName9methodMapSo20FlutterMethodChannelCSo0K15BinaryMessenger_p_SSSDySSypGtFySo0kL4CallC_yypSgctcfU_ + 436
11  plugin_scaffold                     0x0000000102a3266c $sSo17FlutterMethodCallCypSgIegn_Ieggg_AByXlSgIeyBy_IeyByy_TR + 168
12  Flutter                             0x0000000102c2442c __45-[FlutterMethodChannel setMethodCallHandler:]_block_invoke + 116
13  Flutter                             0x0000000102bbfdbc _ZN7flutter15PlatformViewIOS21HandlePlatformMessageEN3fml6RefPtrINS_15PlatformMessageEEE + 680
14  Flutter                             0x0000000102c16654 _ZNSt3__110__function6__funcIZN7flutter5Shell29OnEngineHandlePlatformMessageEN3fml6RefPtrINS2_15PlatformMessageEEEE4$_31NS_9allocatorIS8_EEFvvEEclEv + 80
15  Flutter                             0x0000000102bcd9e8 _ZN3fml15MessageLoopImpl10FlushTasksENS_9FlushTypeE + 132
16  Flutter                             0x0000000102bd209c _ZN3fml17MessageLoopDarwin11OnTimerFireEP16__CFRunLoopTimerPS0_ + 32
17  CoreFoundation                      0x000000019949c564 <redacted> + 28
18  CoreFoundation                      0x000000019949c294 <redacted> + 864
19  CoreFoundation                      0x000000019949bac8 <redacted> + 248
20  CoreFoundation                      0x0000000199496a18 <redacted> + 1844
21  CoreFoundation                      0x0000000199495fc4 CFRunLoopRunSpecific + 436
22  GraphicsServices                    0x000000019b69779c GSEventRunModal + 104
23  UIKitCore                           0x00000001c5e17c38 UIApplicationMain + 212
24  Runner                              0x000000010081aba4 main + 124
25  libdyld.dylib                       0x0000000198f568e0 <redacted> + 4

Weirdly, I can get a BleConnectionState.connected on an iPhone 5s (iOS 12.4.2), but can go no further. I'm using the current version of your library. Perhaps I'm missing something (probably...)?

BTW, I appreciate the work you are doing. Thank you. Hope you can help.